Lapping apparatus



' Feb. 23, 1943. D. A. WALLACE LAPPING APPARATUS I Filed NOV. 7, 1941 FLY Ian 4 INVENTOR H l1 dlldc'e.

' ATTORNEYS.

Patented Feb. 23, 1943 UNITED STATES PATENT OFFICE LAPPING APPARATUS David A. Wallace, Detroit, Mich., assignor to Chrysler Corporation, Highland Park, Mich., a corporation of Delaware Application November 7, 1941, Serial No. 418,107

4 Claims.

The present invention relates to a means for finishing the surface of a cylindrical body, or a cylindrical body having inwardly facing end flanges which are also to be finished. By means of the present invention a high degree of smoothness may be imparted simultaneously to members such as the bearing surfaces and thrust flanges of a crankshaft. A battery of machines embodying the present invention may be em- Fig. 2 is a sectional view taken through the crankshaft and a side elevation of the operating mechanism and tool of the present invention taken substantially along line 2-2 of Fig. 1;

Fig. 3 is a horizontal sectional view through the tool of the present invention taken substantially along line 3-3 of Fig. 2 and looking ployed simultaneously to finish a plurality of in the direction of the arrows; and bearing surfaces and thrust flanges of a multiple Fig. 4 is a sectional View of a portion of the throw crankshaft. operating mechanism taken substantially along The present invention embodies means of the lin of 2 a d looking in the direction type wherein a multiplicity of motions are imof the arrows. parted to the surface finishing tool at the same Th presen nv n n p es a surfaoe ntime that further relative motion between the ishing too In including a longitudinally e dwork surface and the finishing tool is achieved i g r ll ap e obe piv lly Connected y by rotating the crankshaft or other member to p v member l2 o a Connecting link e pbe fini hed during th ti e that th finishing posite end of link l3 being provided with an opentool is in operation. In general, such types of mg s u ly embracing n eccentric I 4 mounted machines and the methods of finishing involved upon the end of a motor shaft l5 driven by m are well-known in the art, and my present intor I6. Motor I6 is mounted upon a frame I? vention comprises specifically a, finishing tool of a Clamp in such position as to have its shaft such character as to be of extreme utility in such extend h the rod t that rotatloh machines and in carrying out such methods of the eccentric I4 imparts rapid reciprocations More specifically, my invention comprises a of short letlgth 9 the operatmg tool T finishing tool adapted to be reciprocated re1a frame I1 is provided with parallel depending tive to a rotating work surface of cylindrical i fifiil g l g fi i i ig gfil ihl zifi o a or cylmdnca'l shape and havmg T-shaped frame guide 22. The leg of the frame ernally facing end flanges thereon, the flmshing 22 ha d t t d tool having front and side working surfaces t e 15 so 5 pe as 0 ex.end ownwa'r and outwardly from the frame in order that the adapted simultaneously to impart a smooth finframe guide may be attached to a bed 24 The ish to the cylindrical surface and the internally bed 24 is adapted to be pivotally mounted l'lpon a faqmg end t The tool compnses table or support 23 by means of trunnions 25 on rahty of h h Stohet so constructed and a pair of spaced trunnion legs 26. A plurality of as posttlvely to lmpart the dfigtee trunnion journals 2'! may be provided in bed 24 of fihlsh to an of the surfaces bemg fimshed for the purpose of shifting the position of the regardless of the amount of Wear to the Working tool respect to a, memb r t b stones have been subjected by previous opera- 40 finished tlons- The frame I! is adapted to be reciprocated lon- A further object of my invention is to provide ,gitudjnany of t frame guide 23 through the a t ol d esser fo reshaping the fi s tool of means of a link 30 pivotally connected to the rear the present invention, in the event that a porof th frame and adjustably and pivota-lly c tion of the finishing tool hould become unduly nected to a T slot operating Wheel 3! driven worn or chipped at its e e o a o prolong the through reducing gearing connected to a motor l f the finishing StoneS- 32 mounted upon the table 23. Longitudinal The for in and th j ts and d nreciprocations of adjustable length are thus imtages of the present invention will be more readparted t th Working tool g by the motor 32 ly appa e t y efe ce to t fo o n sp these reciprocations being out of phase with, and fication taken in connection with the accompanypreferably of a greater amplitude than, th i drawing wherein like numerals refer to like ciprocations imparted by motor I6 soas to cause p r hr ghout. the working surface to change its general rela- In the drawing, Fig. 1 discloses a tool of the tionship to the surface to be finished during the present invention in end elevation as the same time that small portions of the working surface ent disclosure the crankshaft 46 comprises a plu rality of throws 41 and a center bearing portion to permit the crankshaft to.

that the finishing tool is operating upon a portion thereof. In the pres- 48 upon the latter of which the tool is shown in 3 operation in Fig. l. The speed and amplitude of the reciprocations imparted to the tool by mo-" tor 32 will, of course, be so related to the rota- H tions of the crankshaft as to keep some portion of the tool in contact with the surface to be finished at all phases of rotation.

In order that the pressure imparted to the finishing tool maybe controlled .within desirable limits, the frame I! may be provided with an upright peg upon which one or more weights 5! may be mounted. Counterbalancing means is preferably provided by a rearwardly extending peg 52 upon the table 23 upon which one or more weights 53 may beplaced. V

The tool 10 preferably comprises a central extension of rod II from which depend lugs at each end of the tool. The lugs 60 carry transversely extending guide rods 6| upon which-a pair of mounting members 62 are slidably mounted for movement'transversely' of the longitudinal axis of the tool. Springs 63 adjacent each lug 60, having their endssuitably retained in sockets in the mounting members 52, or other resilient means, are adapted to force the mounting members -62 outwardly along the guide rods 6|. Each mounting member carries a finishing stone 6 4. Each stone 64 has a front working surface 65 lying in the plane of the front working surface of the other stone, and each stone has a side working surface 66 lying in Vertical planes parallel to the longitudinal axis of the tool. However, each stone is Wider at one'end than it is at the other, and the stones are placed in reverse position with respect to each other with the Wider end overlapping the longitudinal axis of the tool to a considerable extent. The stones are similarly shaped so that the inner side surfaces are substantially parallel and intersect the longitudinal axis of the tool. Thus, even though the stones may be spread to a considerablev extent by the resilient means 63, each reciprocation of the tool from end to end by the motor 32 will result in overlapping operation byeach tool, thus preventing the formation of high spots by the separation of the stones. A polishing or lubricating fluid may be supplied to the stone through a flexible hose 6'! extending upwardly from the tool. 7

Having described a preferred embodiment of the present invention, it should be apparent to those skilled in the art that modifications in arrangement and detail may be devised. All such modifications 'as come within the scope of the following claims are considered to be a part of my invention. 1 Y

I claim:

1. A surface finishing tool adapted to be reciprocated along its longitudinal axis comprising a pair of finishing stones having front working surfaces lying in the same plane, said stones having parallel, inner side faces lying at an angle to and intersecting the longitudinal axis of the finishing tool so as to permit variable separation of the stones without leaving a clear space therebetween in the direction of the longitudinal axis of the tool, and mounting means for said stones permitting variable separation thereof in a di- "rection substantially normal to the longitudinal axis of the tool.

2. A surface finishing tool adapted to be reciprocated along its longitudinal axis comprising a pair of finishing stones having front Working surfaces'lying in the same plane, said stones having parallel, inner side faces lying at an angle to and intersecting the longitudinal axis of the finishing tool so as to permit variable separation of the stones without leaving aclear space-tl'1ere between in the direction of the longitudinal axis of the tool, and mounting means for said stones permitting variable separation thereof'in a direction substantially normal tothe longitudinal axis of the tool, and resilient means urging said stones apart along said mounting means.

3. A surface finishing tool for simultaneously finishing a cylindrical body-and the'inwardly facing surfaces of end flanges thereon suchas the crankpin and thrust flanges of a" single throw of a crankshaft, comprising a pair of longitudinally extending mounting members, guide means upon which said mounting members are slidably positioned, saidguide means extending normal to thelongitudinal'axis of thefinishing tool so as .to permit movement ofsaid mounting members toward-or away from the longitudinal axis of the finishing tool,- resilient means tending to separate said mounting members,-and-a-finishing stone mounted on each of said; mounting members, said stones having front working surfaces lying in the same plane, and each of said stones having an outer side .working surfacesubs'tam tially. parallel to the, longitudinal- 1 axis .,'of the finishing tool and an inner side surface'an'gulaily intersecting the longitudinal axisfof the finishing tool. 4. A surface finishirig' tool for simultaneously finishing a cylindrical body' and. 'the.inwardly facing surfaces of endfianges thereon such as the crankpin and thrust flanges of a single'throw of a crankshaft, comprising a pair of longitudi nally extending finishing stones,,means mounting said finishing stones forimovement to'ward and away from each otherji'n a plane normal to the longitudinal axis ofthe finishing tool, and resilient means tending to separate said finishing stones, each of said stones having a front work; ing surface lying in a plane parallel to the plane of movement thereof toward and away from ea'ch other, an outer side working surface substantially parallel to the longitudinal axis of the finishing tool and an inner sidesurface 'a'ngularlyi intersecting the longitudinal axis of the finishing. tool; said inner side surfaces lying in substantial par-l allelism so that the front working surfaceiof each stone extends across the longitudinal axisofgthe finishing tool; 2 i, -DAVID A. WALLACE. 

